Clements speaks both Chinese and Japanese, and many of his works relate to East Asia. He wrote his Master's degree at the University of Stirling on manga and anime exports, predicting the rise of several trends in the international industry including back-to-front printing, direct American investment in anime, and the proliferation of attempts to substitute non-Japanese products. Subsequently, he translated over 70 anime and manga works for British distributors, and worked as a voice director and actor. He wrote his PhD at the University of Wales on the industrial history of Japanese animation, later published by the British Film Institute as Anime: A History.
He served two years at Titan Books in London as the editor of Manga Max magazine, an experience he would later fictionalise as the Judge Dredd adventure Trapped on Titan. In 2000, he received the Japan Festival Award for Outstanding Contribution to the Understanding of Japanese Culture, specifically for his work on Manga Max.